A sliding device is disclosed in U.S. Pat. No. 5,351,975, wherein the turning slide is round-shaped and the supporting slide is essentially a rectangular plate having a rounded front end. A stabilizing bar is provided between a sleeve in which the fork is rotatable and the front end of the supporting slide, so that this stabilizing bar is positioned before the rider's feet, which are to be positioned on a supporting plate provided on the supporting slide.
Such a sliding device presents some problems. Since the front portion of the turning slide is round-shaped, the sliding device cannot move in a straight line properly. While the sliding device moves forward in curves, the length of the edge of the turning slide in contact with the snow is relatively short; therefore, the edge effect does not function well and changing direction is difficult.